SOLUTION: what is the equation required to create a simple wine glass in a graph and how can we find its volume?

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Question 621373: what is the equation required to create a simple wine glass in a graph and how can we find its volume?
Answer by KMST(5328) About Me  (Show Source):
You can put this solution on YOUR website!
Since you placed that question under "Quadratic Equation", I assume the expected profile is a parabola, the graph of a quadratic function. I inspected all the wine glasses in my china cabinet and in my wine cupboard and concluded that a paraboloid is not the shape of a wine glass. The mouth of the glass is never the widest part. Wine glasses can be shaped like truncated ellipsoids (white wine glasses) or have a truncated egg shape (with the tip cut off). The bulb of wine glasses is not shaped like a paraboloid, but I guess a paraboloid is the simple shape envisioned. (I would suggest a truncated ellipsoid, but you may not have studied ellipses yet).
I also assume that you are in a Calculus class and were taught how to use integration to find the volume of a solid of revolution.
If the height above the bottom of the bulb is h and the cross-section radius is x, the shape of a paraboloid wine glass bulb would given by
h=ax%5E2 <--> x%5E2=h%2Fa
A cross section of the glass is a circle with area pi%2Ax%5E2,
and since x%5E2=h%2Fa, that cross section area would be pi%2Ah%2Fa
If the height of the bulb (vertical distance from the rim to the bottom of the bulb) is H, the volume could be calculated as
V=int%28%28pi%2Fa%29%2Ah%2Cdh%2C0%2CH%29
If you use centimeters, then you would get the volume in cubic centimeters, which are essentially the same as milliliters.
I would chose something close to 6-8 cm for the diameter at the top, and 10 cm for the height (H) of the wine glass bulb.
With a paraboloid shape, and an 8-cm top diameter, you have x=4 and h=10 at the rim, so
10=a%2A4%5E2 --> a=10%2F16=5%2F8.
In that case
V=int%28%285pi%2F8%29%2Ah%2Cdh%2C0%2C10%29=%285pi%2F8%29%2A10%5E2= about 196 mL